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Topic: Cetus3D 3D Printer (Read 8630 times)

There is a little blemish on each of them down one corner of the side, and I presume its where the extruder is changing level - but even trying to avoid it when measuring there is still a fair difference

All things considered I'd still say that is one helluva deal, Mr. Mawson. My original Prusa I3 MK2 does slightly better but not much and that is 3-4 times the price! Might have to look into this one myself actually... even if I need another 3D printer about as much as I need a hole in my head...

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Henning

Just because i can't, doesn't mean i shouldn't? Tool- lover, with a collection to show for it!

Well the prints are pretty close to the ± 0.1mm tolerance. The width difference could be put down to a combination of mechanical things working against you in that area. Slight difference in belt pitch or a pulley slightly off centre. Possibly a little spring in the table at that point that just adds a little squeeze to each layer printed. If it is that, then it maybe a limit you are stuck with. 1cm squares 5mm tall in different locations, map them and mark them before removing from the bed for comparison. What was the Z dimension on this two parts you made, are they identical ? Bit hard to measure as the raft can contribute to Z error. Hence my calibration cubes are printed direct onto 3M tape directly on the bed.

I print about 20 or so of my calibration cubes per machine during a tune up.

The seam you are seeing is the step to the next layer, usually there is an option to have random starts for new layers to try and hide the seam. This can contribute to small blobs on the print side as the flow is stopped and started in a new position. A single seam is easier to treat as a post process and has less issue with stop start of the filament flow.

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Just get doing and make swarf, you can decide what its going to be later.

Joules, I don't see the error in width as a mechanical issue. For one of the Peggy's the width was X axis and for the other it was Y, and of course this is also true of the lengths, which are absolutely spot on. So both X and Y axis are producing accurate movement.

I reckon that the shape of the model is allowing cooling stresses to affect the width far more than the length

Do your previous prints measure identical ? Unless you have a draught blowing on one side of the printer, cooling should be pretty consistent. It can still contribute, but you would see it in X,Y error.

Think of a sine wave with a straight line average. Your tolerance has varied over different size in different location. Depends how much you want to chase the tolerance. My experience in what you see is a very slight eccentricity in one or more of the pulleys. Maybe an over tightened grub screw etc.

The sides will exhibit distortion, bulge or hollow if they cool differently, it wouldn't remain square.

« Last Edit: May 08, 2017, 03:22:57 AM by Joules »

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Just get doing and make swarf, you can decide what its going to be later.

Keep in perspective, 0.1mm difference I would ignore, you are only 50 micron !!! over. Not bad out of the box if this is representative for this machine. I do hope they get imported into the UK by someone.

Forgot early on to ask what are all the peg dimensions in X,Y The same ?

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Just get doing and make swarf, you can decide what its going to be later.

That's probably a question for Joules, though I know flexible filament is available, being a thermo-plastic there will be temperature constraints.

This is fun - I've just created a 'Clip' in Fusion360 to hold the Poly-carbonate screens together on my Wire EDM machine to replace the crude use of cable 'p-clips' - if the proto-type fits then I'll make a further 5 of them

Sorry, printed elastomers are outside my zone, I have found none to have characterristics I would be happy with. However, what I have done is print moulds and cast my own soft rubber/gasket type components.

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Just get doing and make swarf, you can decide what its going to be later.

Well today my ambition knew no bounds with the Cetus3D printing solidly all day making my biggest print yet - a spool / reel holder for the filament that clips onto the body of the printer, rather than being a separate item.

The design is not mine, I lifted it from the Cetus forum, though it is also on Thingyverse - no point in re-inventing the wheel

The basic frame - the black bit in the pictures took over 6 hours to print, and the white supporting peg took almost 3 hours, so the poor little printer has been churning away for over nine hours solid.

Interesting design with the two parts screwing together with a coarse printed thread. The black base is pretty well as big as the print bed, so although I can print taller I cannot make things of a much larger cross section. The white peg was a bit of a pain to separate from it's supporting structure (the stuff that makes temporary scaffolding for the construction.)

Andrew, The bit, "(the stuff that makes temporary scaffolding for the construction.)" is called a raft, I guess cos the part 'floats' on it. Only know this from reading other post re, 3D printers. Three or four of the blokes at my club have em. I find them interesting but have no room nor $ for them. Also read of putting masking tape (think it has to be the blue, not the cheapo stuff.) on the platform and telling the program not to lay a raft. You are making stuff and that's always good.

John B

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Converting good metal into swarf sometimes ending up with something useful. ;-)

Thanks John but I was avoiding using the word raft, as the raft was dead easy to remove.

It was the supports for the overhang, which were quite extensive on the peg, that were hard to remove. The threaded screw had to be at the bottom of the print to ensure it would fit, hence a lot of the rest of it with its flanges was out in free space and would fall without the scaffold support.

Thanks Andrew, As my 8yr old grandson says about school, "I learn stuff here". Looking again at your photos, I can see what you mean about the supporting structure betwixt the raft and flange located above the screwy bit. That would definitely require some careful removal or a wrecked part could easily result.

John B Edit, Just had another look and there was more support around the spool bit to stop the upper flange drooping. Lots of scaffolding / supporting stuff to remove.JB

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Converting good metal into swarf sometimes ending up with something useful. ;-)

On the subject of printing gaskets, I would say that is entirely possible. I am experimenting with a material called cheetah which is a thermoplastic elastomer. A quick google will probably bring up the relevant tecspec for anyone interested. I do believe this would be a suitable material for gaskets in low pressure and low temperature cases. I have not printed any gaskets in it yet, but I did make an elastic cover for my iPhone which worked out pretty good.

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Henning

Just because i can't, doesn't mean i shouldn't? Tool- lover, with a collection to show for it!

On the subject of printing gaskets, I would say that is entirely possible. I am experimenting with a material called cheetah which is a thermoplastic elastomer. A quick google will probably bring up the relevant tecspec for anyone interested. I do believe this would be a suitable material for gaskets in low pressure and low temperature cases. I have not printed any gaskets in it yet, but I did make an elastic cover for my iPhone which worked out pretty good.

Thank you....So far I haven't seen too much use domestic 3D printers, but printing elastomer, structural plastics and possibly some (slide) bearing material would expand a whole lot use. Specially if I could fabricate/mill/turn part in aluminium and then "print" gasket and/or cover into it.

As I understand it, printing on or into existing parts is still not very easy with the regular "home gamer" machines. I do think it will probably be introduced at some point though. Probably not until the materials get better though. I have a spool of Nylon with which I intend to try and print some parts. If that works out ok, I'd say we're closing in on game changing technology!

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Henning

Just because i can't, doesn't mean i shouldn't? Tool- lover, with a collection to show for it!

I did some search and fast reading on thermoset elastic filaments to 3D printers and they seem to be available, they seem to work on same envelope than ABS. PLA-only printers does not seem to work them.

Biger obstacle to me is the SW side. I'm slow learner, but when I learn something it comes hardwired and almost automatic. CAD is another thing altogether, but slicer is the part that feel iffy.

How can print elastomer (ar any other stuff) over prefabricated part? Can slicer be used to sellectively start printing at certain "height" or can you set and tweak height contour?

Printter table should ofcourse be able to support the part like aluminium light weight eclosure.

Probably faster approach would be to print alastomer on PA or ABS part or carrier/sandwich and accomondate that into design.